Dirty Secrets
by BMShipper
Summary: Mark has a dirty little secret, Derek finds out, not expecting his own dirty little secret to come out... Mark/Jackson with other implied pairing


A/N: So… my 3rd One-Shot about Jackson and Mark, and the boys got me hooked bad… seriously, I can't stop writing about them, and there are at least 3 more One-Shots about to come, once they come back from my beta! *winks at beta* THANKS FOR YOUR HELP!

This One-Shot is dedicated to my dear friend Megan by the way, who gave me the idea and who is a huge Derek/Owen Fan… :-)

Comments would be great… tell me whether you liked or didn't like this One-Shot! And now have fun! :)

**Dirty Secrets**

„So… how long have you and Avery been sleeping together?" Derek asked with an almost innocent look on his face.

Mark's jaw dropped, the shock on his face clear as he replied to his best friend. "What?"

"You heard me," Derek replied, folding his arms on his chest and leaning against the doorframe of the on-call room.

"Why do you think I'm sleeping with Jackson?" Mark asked, raising one eyebrow.

"I was suspicious but you just confirmed it," Derek grinned.

Mark tilted his head and tried to keep a straight face. "Why? Because I'm calling him Jackson now? We're friends. Like you and I."

"That and the fact that I saw you both disappear in here and ten minutes ago Avery came out with this satisfied 'I just had sex' expression," Derek explained calmly.

"Are you spying on me now?" Mark complained, still not answering Derek's question. He felt bare and he definitely didn't want to pull Jackson into this conversation without him being able to defend himself. Also, he didn't want to out him, out them.

"No, I'm not spying!" Derek assured Mark. "But you haven't been very careful. You're lucky that it was only me who saw you and not Lexie. I'm sure she would have totally lost it."

"We're not together anymore. It's none of her business," Mark shot back, even though he got Derek's point and he knew Derek was right. If Lexie would ever find out that two of her ex-boyfriends were having an affair with each other she would never forgive either of them. Regardless, it wasn't something Mark had intended to do, it just happened.

Ever since Jackson broke up with Lexie the two of them had started hanging out, a lot. There had always been some tension between them, but one night it became almost unbearable. They were watching a football game on TV and Mark had complained about a pain in his neck. When Jackson had offered him a massage, he _of__course_ hadn't said 'no'. He hadn't expected Jackson to be _this_talented with his hands, and Jackson had gotten him hard within minutes. He had felt like a horny teenager. It had felt so good, to have Jackson's magic hands on his body and Mark had become aware of the fact that although he wasn't into guys, he most likely was into Jackson. He had tried to hide his problem first, but he couldn't fool Jackson and when he had turned around to face him again, Jackson had kissed him. Hard. The night ended with them making out heavily, making each other come a few times until they fell asleep on Mark's bed later. Mark didn't even know how they made it into his bedroom anymore, but somehow they managed to get there.

That was two weeks ago and since then they were having sex almost every day. They met whenever they didn't have to work – mostly at Mark's place, because they were uninterrupted there. At least that was the case most of the time. A few days ago Callie had almost caught them in action when she entered Mark's apartment without knocking to bring over Sofia, but Jackson had managed to hide in Mark's wardrobe in the very last moment and hadn't come out until she was gone.

"No, you're right, it's none of her business. But I still think you shouldn't be so careless. I'm pretty sure Avery doesn't want anyone to know your little secret." It was Derek's voice that brought Mark back to reality and he looked at him, rubbing the back of his neck.

"So it's really_this_ obvious?" he asked, feeling a little bit embarrassed. He didn't even try to deny it. Why would he? Derek knew him well enough to notice when he was lying.

"Don't worry, it isn't," Derek reassured him. "But you're my best friend, and I know you well enough to sense when something in your life changes."

Mark nodded looking at him. He didn't know if he should say something, so he remained silent.

"Why didn't you tell me? I thought you trusted me," Derek questioned him, taking a step towards Mark.

Mark shrugged. "I don't know. Maybe because I don't know what I should have told you, I mean, it's not like Jackson and I are together…" He ran his hand through his hair almost desperately. "Hell, I don't even know what there is between us."

"But you like him," Derek stated as if it was a fact.

"No!" Mark blurted out; then he hesitated for a moment before adding a much quieter "Yes."

"I thought so," Derek smiled, placing a consolingly hand on Mark's shoulder. "Maybe you should talk to him."

Mark shrugged. "Maybe I should. I will think about it," he promised, because he knew Derek wouldn't let it go otherwise.

For a few moments the two of them stood in front of each other in silence, until Derek started speaking again.

"I thought we wouldn't do guys ever again?" A mischievous grin appeared on his lips.

Mark knew exactly what Derek was referring to and grinned back at him. "Apparently I changed my mind. Maybe you weren't good enough back then."

"Hey!" Derek complained and punched Mark in his ribs. "Maybe _you_ weren't good enough. Or maybe we were too young and inexperienced."

They shared a knowing look and Mark couldn't help but think about their one night back at med-school. Derek and he were celebrating a successful exam. They had been very drunk when they had started kissing and making out, and in the end they had even slept together. They had been so drunk that Mark hadn't even remembered much the next morning, but most of it had come back little by little. For almost two decades Derek had been the only guy Mark had ever touched like that, and he had had no intention of ever doing it again.

Until Jackson came into his life and slowly but surely stole his heart. He didn't know if Jackson felt anything for him, or if it was just sex, but he was afraid to ask, either, because he wasn't ready to lose him just yet. He wanted to enjoy what they had and he would, as long as it lasted.

"Maybe we were," Mark finally answered, looking at his best friend.

Suddenly the door swung open and would have hit Derek in the back if Mark hadn't pulled him aside in time.

Before Mark knew what hit him, he watched Owen Hunt grab Derek's hips and push him against the wall before pressing his lips against Derek's and starting to kiss him.

"I saw you coming in here and I couldn't resist. It's been way too long since last night. I'm so horny and I want you so bad," he heard Owen mumble in between two kisses and just stared at the two men in shock.

Hunt and Derek? How was this even possible and why didn't he notice anything at all? He knew Derek and Meredith's marriage had never been easy, and Derek had told him that Hunt and Yang had some problems as well, but _this_? This was beyond belief.

It took him a few seconds before he was able to draw attention to himself by clearing his throat.

Owen jerked away from Derek and stared at Mark outraged.

"Oh my God. I didn't see that someone else was in there," he admitted, biting his lower lip.

Mark had to fight back a grin. "I noticed that," he replied, patting Owen's shoulder while passing him by. "Don't worry, your secret is safe with me."

He winked at Derek, whose cheeks were slightly flushed, leaning over to him.

"I thought we wouldn't do guys ever again?" he repeated Derek's question from before in a whisper.

"Apparently I changed my mind," Derek whispered back with a smile on his lips.

Mark opened the door and was out in a matter of seconds. He heard the door lock clicking behind him and couldn't hold back the grin crossing his lips. Obviously he wasn't the only one with a dirty secret in the hospital.


End file.
